John Corbett's run of good luck began with his role as dreamy DJ Chris Stevens on CBS' sleeper ''Northern Exposure.'' He later exuded the same laid-back aura -- and recurred for far too long -- as Aidan Shaw on ''Sex and the City.'' (Did anybody believe Sarah Jessica Parker's cosmopolitan Carrie would find true love with an outdoorsy carpenter?) Then Corbett stumbled into a little movie called ''My Big Fat Greek Wedding.''
After ''Greek Wedding'' became the highest-grossing romantic comedy in history, Corbett's luck appeared to have run out. Screenwriter-star Nia Vardalos and the rest of the film's ensemble signed on for a CBS sitcom spin-off, the surefire hit My Big Fat Greek Life, but John Corbett couldn't join them since he'd agreed to headline the obscure basic-cable dramedy ''Lucky.'' As it turns out, though, fortune may still be smiling on him. ''Greek Life'' is a big fat bummer, and FX is suddenly the hot network, thanks to its Emmy and Golden Globe victories for ''The Shield.''
Steven Eckholdt (''It's Like, You Know...''), who replaces Corbett as Vardalos' WASPy husband in ''Greek Life,'' aspires to a Corbettesque coiffure but falls short in this and other areas. While Corbett was typically relaxed, Eckholdt comes across as tentative -- the new kid in Greek class.
His performance isn't the only difference between the sitcom and the movie. The newlyweds have been renamed (Nia and Thomas instead of Toula and Ian) and they now live across the street from her family's diner instead of next door to her pushy parents (uncured hams Michael Constantine and Lainie Kazan). The latter change was probably made to keep ''Greek Life'' from seeming too similar -- and paling in comparison -- to ''Everybody Loves Raymond.''
Vardalos, who developed the series with ''Just Shoot Me'''s Marsh McCall, pops her eyes wide open on almost every punchline, but she really should expend more energy punching up the tired scripts. As her dumb but lovable brother, Nick, Louis Mandylor is playing a sitcom cliché (he might as well be named Joey Tribbianopoulos), and Gia Carides has been given little to do as cousin Nikki besides show off her voluminous cleavage. Only ''SCTV'' vet Andrea Martin, as Aunt Voula, elicits laughs by the sheer force of her heavily accented delivery.
You can hardly blame an actor like Eckholdt for phoning it in when he's given nonjokes like this: ''In my family, Sunday night is always dispute-resolution night: dinner, '60 Minutes,' followed by a respectful, healthy debate of family issues.'' At least his family doesn't stay tuned for ''My Big Fat Greek Life'' -- which makes them almost as lucky as John Corbett.